diff options
Diffstat (limited to 'include/linux/dma-direct.h')
| -rw-r--r-- | include/linux/dma-direct.h | 127 |
1 files changed, 127 insertions, 0 deletions
diff --git a/include/linux/dma-direct.h b/include/linux/dma-direct.h new file mode 100644 index 000000000..18aade195 --- /dev/null +++ b/include/linux/dma-direct.h @@ -0,0 +1,127 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * Internals of the DMA direct mapping implementation. Only for use by the + * DMA mapping code and IOMMU drivers. + */ +#ifndef _LINUX_DMA_DIRECT_H +#define _LINUX_DMA_DIRECT_H 1 + +#include <linux/dma-mapping.h> +#include <linux/dma-map-ops.h> +#include <linux/memblock.h> /* for min_low_pfn */ +#include <linux/mem_encrypt.h> +#include <linux/swiotlb.h> + +extern unsigned int zone_dma_bits; + +/* + * Record the mapping of CPU physical to DMA addresses for a given region. + */ +struct bus_dma_region { + phys_addr_t cpu_start; + dma_addr_t dma_start; + u64 size; + u64 offset; +}; + +static inline dma_addr_t translate_phys_to_dma(struct device *dev, + phys_addr_t paddr) +{ + const struct bus_dma_region *m; + + for (m = dev->dma_range_map; m->size; m++) + if (paddr >= m->cpu_start && paddr - m->cpu_start < m->size) + return (dma_addr_t)paddr - m->offset; + + /* make sure dma_capable fails when no translation is available */ + return DMA_MAPPING_ERROR; +} + +static inline phys_addr_t translate_dma_to_phys(struct device *dev, + dma_addr_t dma_addr) +{ + const struct bus_dma_region *m; + + for (m = dev->dma_range_map; m->size; m++) + if (dma_addr >= m->dma_start && dma_addr - m->dma_start < m->size) + return (phys_addr_t)dma_addr + m->offset; + + return (phys_addr_t)-1; +} + +#ifdef CONFIG_ARCH_HAS_PHYS_TO_DMA +#include <asm/dma-direct.h> +#ifndef phys_to_dma_unencrypted +#define phys_to_dma_unencrypted phys_to_dma +#endif +#else +static inline dma_addr_t phys_to_dma_unencrypted(struct device *dev, + phys_addr_t paddr) +{ + if (dev->dma_range_map) + return translate_phys_to_dma(dev, paddr); + return paddr; +} + +/* + * If memory encryption is supported, phys_to_dma will set the memory encryption + * bit in the DMA address, and dma_to_phys will clear it. + * phys_to_dma_unencrypted is for use on special unencrypted memory like swiotlb + * buffers. + */ +static inline dma_addr_t phys_to_dma(struct device *dev, phys_addr_t paddr) +{ + return __sme_set(phys_to_dma_unencrypted(dev, paddr)); +} + +static inline phys_addr_t dma_to_phys(struct device *dev, dma_addr_t dma_addr) +{ + phys_addr_t paddr; + + if (dev->dma_range_map) + paddr = translate_dma_to_phys(dev, dma_addr); + else + paddr = dma_addr; + + return __sme_clr(paddr); +} +#endif /* !CONFIG_ARCH_HAS_PHYS_TO_DMA */ + +#ifdef CONFIG_ARCH_HAS_FORCE_DMA_UNENCRYPTED +bool force_dma_unencrypted(struct device *dev); +#else +static inline bool force_dma_unencrypted(struct device *dev) +{ + return false; +} +#endif /* CONFIG_ARCH_HAS_FORCE_DMA_UNENCRYPTED */ + +static inline bool dma_capable(struct device *dev, dma_addr_t addr, size_t size, + bool is_ram) +{ + dma_addr_t end = addr + size - 1; + + if (addr == DMA_MAPPING_ERROR) + return false; + if (is_ram && !IS_ENABLED(CONFIG_ARCH_DMA_ADDR_T_64BIT) && + min(addr, end) < phys_to_dma(dev, PFN_PHYS(min_low_pfn))) + return false; + + return end <= min_not_zero(*dev->dma_mask, dev->bus_dma_limit); +} + +u64 dma_direct_get_required_mask(struct device *dev); +void *dma_direct_alloc(struct device *dev, size_t size, dma_addr_t *dma_handle, + gfp_t gfp, unsigned long attrs); +void dma_direct_free(struct device *dev, size_t size, void *cpu_addr, + dma_addr_t dma_addr, unsigned long attrs); +struct page *dma_direct_alloc_pages(struct device *dev, size_t size, + dma_addr_t *dma_handle, enum dma_data_direction dir, gfp_t gfp); +void dma_direct_free_pages(struct device *dev, size_t size, + struct page *page, dma_addr_t dma_addr, + enum dma_data_direction dir); +int dma_direct_supported(struct device *dev, u64 mask); +dma_addr_t dma_direct_map_resource(struct device *dev, phys_addr_t paddr, + size_t size, enum dma_data_direction dir, unsigned long attrs); + +#endif /* _LINUX_DMA_DIRECT_H */ |